Fabrication Of Porous Honeycomb Films And Their Biological Function

In recent years, polyoxometalates (POMs) spark a wide interest in the field of assembling with other materials. POMs are novel inorganic macromoleculars, and as many of them contain a large number of water ligands, they are quite soluble in polar solvents. In the solution, they are negatively charged, with the negative charge balanced by small counterions such as Na+. Based on electrostatic interaction, POMs can be modified by surfactants with opposite electric charge. Recent progress in assembling hybrids surfactant-encapsulated polyoxometalates,(SEP) will exhibit ordered structures on solid substrates under the moist condition.In the thesis, we studied the methods and conditions of building orderly porous films, structure morphology and properties of porous membranes. And honeycomb porous films are used as bacteriostatic agent. The membranes show significant anti-hepatitis virus replication function and cellular compatibility. The outline and contents of this dissertation are as follows:Chapter1is a brief introduction of research background of this thesis in which assembly methods, classification, characteristics and applications of POMs are reviewed. Second, we summarized the interaction between POMs and suitable surfactants, and behavior of assembly SEP in the solution or interface. SEP can be self-assembly and form orderly structures. After that, we emphatically introduce the current research status of porous membranes and the latest progress. Recently, the researchers mainly report fabricating honeycomb porous films by polymers on solid substrates, but seldom research in SEP. Because of functional applications of the porous films, especially in the biological medicine research value, we put forward the purpose of this thesis.In Chapter2, ordered honeycomb films based on SEP on solid substrates were obtained by solvent evaporation method, and characterized the morphology and structure of porous membranes. First of all, the POM Na11[CoW11O39]·6H2O ({CoW11}) was synthesized in this thesis. Secondly, hydrophobic double-chain cationic surfactants dioctadecyldimethylammonium chloride (DODMA+Cl-) and dihexadecyldimethylammonium bromide (DHMA+Br-) were used to modify POM. And SEP was self-assembly on solid substrates with a humid airflow across the solution surface by solvent evaporation method to fabricate honeycomb porous films. SEM, AFM, TEM results show the ordered structure of honeycomb porous films.In Chapter3, the porous films were proved to have inhibition from E. coli, S. aureus, P. aeruginosa and hepatitis virus. We employed different methods as growth inhibition test, bacteria counting, MTT method and cell culture method to do experimental research. This kind of film can be used for waste water treatment, loading drug, bacteria separation and liver disease treatment. The aperture of the porous films can be controlled by changing the type of surfactant and concentration to meet the practical application of various circumstances.In Chapter4, the biocompatibility of honeycomb porous membrane was studied. Many cell toxicity experiments prove that the films are non-toxic and not hemolytic to normal cells. That greatly widened the scope of application of the film. Therefore, the biological compatibility films can be used in blood filter and clinical treatment.In Chapter5, we summarized the preparation and application of the honeycomb porous films. The research enriches the nanoscale polyoxometalates chemistry, and promots the development of the interfacial film. It is of great importance in building orderly functional materials.